Download Electricity Web Review File

Electricity Web Review
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the
statement true.
____
1. In many circuit diagrams, any electrical device that uses energy is shown with a resistor symbol.
_________________________
____
2. A closed circuit has a break in it. _________________________
____
3. An ohm is the unit of measurement for current. _________________________
____
4. Electric current will flow easily through a conductor. _________________________
____
5. A series circuit contains branching points and multiple paths for current to flow through.
_________________________
____
6. The coulomb is the unit of measure for charge. _________________________
____
7. The electric force between two charged objects increases as the distance between them increases.
_________________________
____
8. Some of the electrons in insulators are free to move throughout the material.
_________________________
____
9. An electroscope is a device that can be used to observe electric forces. ________________________
Completion
Complete each statement.
10. A complete path through which electricity travels is called a ____________________.
11. A device used to create an intentional break in a circuit to stop the flow of current is a
____________________.
12. Differences in ____________________ cause charge to flow.
13. A battery uses ____________________ energy to move charges.
14. Fuses protect a circuit from too much current by creating a break in the circuit but must be replaced. A
device that may be reset while providing the same protection is a _________________________ (two
words).
15. According to Ohm’s law, resistance is the ratio of ____________________ to ____________________.
16.
As shown in the graph above, plotting voltage on the x-axis and current on the y-axis, the slope of the
resulting line represents the ____________________.
17. The build up of electric charge on an object is called ____________________ electricity.
18. An object with equal amounts of positive and negative charge is called ____________________.
Short Answer
19. Explain how a potentiometer is different from a fixed resistor.
20. The circuit shown below has 3 identical bulbs connected in series to a battery. If 1 bulb is unscrewed, what
will happen to the 2 remaining bulbs?
21. Name the two factors that determine the strength of the electrical force between two charged objects, and
describe how these two factors influence the force between the two objects.
22. If the distance between charges is reduced by half, what happens to the force between them?
23. What does the term “charging by friction” mean, and what happens to the charge of the objects involved?
Give one example.
Problem
24. Which of the circuits pictured below is an open circuit?
25. What should the voltmeter read (approximately)?
26. A miniature light bulb with a resistance of 3 ohms is connected to a 6-volt source. How much current will
flow through the bulb?
27. If the current moving through the filament of a light bulb is 0.5 amps when the voltage across the bulb is
120 volts, what is the resistance of the bulb?
A simple circuit is pictured in Figure 13-1. A light bulb is connected to a 9-volt battery that causes 3 amps
of current through the bulb:
28. What is the resistance of the light bulb in the circuit shown in Figure 13-1?
29. If the light bulb in the circuit shown in Figure 13-1 is replaced with a light bulb having a resistance of 9
ohms, what would the new current in the circuit be?
30. If a second 9-volt battery is stacked with the battery shown in the circuit in Figure 13-1, what would the
new current in the circuit be?
31. A series circuit contains a 9 volt battery and three resistors of 1 ohm, 3 ohms, and 5 ohms. What is the
current in the circuit?
Essay
32. What are two similarities between gravitational force and electric force?
33. Describe the three processes that are used to charge objects.
Other
The circuit pictured contains a light bulb connected to a voltage source that causes 2 amps of current
through the bulb.
Figure 13-2
34. Draw a circuit diagram to represent the circuit in Figure 13-2 using electrical symbols.
The circuit pictured contains 3 identical light bulbs. They are connected to a voltage source which causes 2
amperes of current to flow through each of the bulbs.
Figure 14-1
35. Identify the type of circuit in Figure 14-1.
Electricity Web Review
Answer Section
MODIFIED TRUE/FALSE
1. ANS: T
REF: section 13.1
2. ANS: F, open
PTS: 1
3. ANS: F, resistance
PTS:
1
DIF:
basic
DIF:
basic
REF: section 13.1
PTS:
4. ANS:
REF:
5. ANS:
1
DIF:
T
section 13.3
F, parallel circuit
basic
REF: section 13.3
PTS: 1
DIF:
basic
PTS:
6. ANS:
REF:
7. ANS:
1
T
section 15.1
F, decreases
basic
REF: section 14.2
PTS: 1
DIF:
basic
DIF:
basic
DIF:
PTS: 1
DIF:
8. ANS: F, conductors
intermediate REF: section 15.1
PTS: 1
9. ANS: T
REF: section 15.2
basic
DIF:
REF: section 15.2
PTS: 1
COMPLETION
10. ANS: circuit
PTS: 1
11. ANS: switch
DIF:
basic
REF: section 13.1
PTS: 1
12. ANS: voltage
DIF:
basic
REF: section 13.1
PTS: 1
13. ANS:
DIF:
basic
REF: section 13.2
chemical
potential
PTS: 1
DIF:
14. ANS: circuit breaker
basic
REF: section 13.2
PTS: 1
DIF:
15. ANS: voltage, current
basic
REF: section 13.2
PTS: 1
16. ANS: resistance
DIF:
intermediate REF: section 13.3
PTS: 1
17. ANS: static
DIF:
advanced
REF: section 13.3
PTS: 1
18. ANS: neutral
DIF:
basic
REF: section 15.1
DIF:
basic
REF: section 15.1
PTS:
1
SHORT ANSWER
19. ANS:
A potentiometer can be adjusted to give a range of resistance; a fixed resistor has a resistance that
cannot be changed.
PTS: 1
20. ANS:
DIF:
intermediate REF: section 13.3
The other two bulbs will go out when one bulb is unscrewed.
PTS: 1
21. ANS:
DIF:
basic
REF: section 14.1
The two factors are the amount of excess charge on the objects and the distance between them.
The force is stronger when the amount of charge is greater and when they are closer together.
PTS: 1
22. ANS:
DIF:
intermediate REF: section 15.1
The force between charges is inversely proportional to the square of the distance between them.
Halving the distance increases the force by 4 times.
PTS: 1
23. ANS:
DIF:
intermediate REF: section 15.1
Charging by friction occurs when two neutral objects are rubbed together, and charge is
transferred from one to the other. One object loses negative charge. Objects charged in this
manner have opposite charges and attract each other.
Examples may vary. Correct examples include:
clothes from a dryer, certain semi-precious stones rubbed with fabric, a glass rod rubbed with
silk, a person dragging your feet over a floor or carpet
PTS:
1
DIF:
advanced
REF: section 15.1
PTS: 1
25. ANS:
DIF:
basic
REF: section 13.1
PROBLEM
24. ANS:
A
voltage of cell #1 + voltage of cell #2 = voltage of meter
1.5 volts + 1.5 volts = 3.0 volts
PTS: 1
26. ANS:
DIF:
intermediate REF: section 13.2
PTS: 1
27. ANS:
DIF:
intermediate REF: section 13.3
PTS: 1
28. ANS:
DIF:
intermediate REF: section 13.3
PTS: 1
29. ANS:
DIF:
intermediate REF: section 13.3
PTS: 1
30. ANS:
DIF:
advanced
REF: section 13.3
PTS: 1
31. ANS:
DIF:
advanced
REF: section 13.3
resistance = voltage current (or) R = V I
current = voltage resistance = 6 volts 3 ohms = 2 amps
PTS:
1
DIF:
intermediate REF: section 14.1
ESSAY
32. ANS:
Any two of the following three answers are correct:
1) Both gravitational force and electric force are due to a fundamental property of matter. For
gravitational force, the property is mass, and for electric force, the property is charge.
2) More charge results in stronger electric force; more mass results in stronger gravitational force.
3) Both forces decrease as distance increases, following an inverse square law.
PTS: 1
33. ANS:
DIF:
advanced
REF: section 15.1
1) Charge by induction: No contact is made between the charged object and the object being
charged. Placing the charged object close by forces electrons to move in the object being charged.
Grounding the object being charged causes electrons to move into or out of it and allows it to
have a net charge. The original object’s net charge does not change.
2) Charge by friction: By rubbing two objects together, electrons are transferred between the two
objects. One object gains electrons and has a negative net charge. One object loses electrons and
has a positive net charge.
3) Charge by contact: Contact is made between a charged object and a neutral object. Electrons
are transferred between the two objects and the neutral object becomes charged.
PTS:
1
DIF:
advanced
REF: section 15.1
1
DIF:
intermediate REF: section 13.1
OTHER
34. ANS:
PTS:
35. ANS:
It is a parallel circuit.
PTS:
1
DIF:
basic
REF: section 14.2